High based showers track across northeast Colorado on the afternoon and evening of June 25th producing wind gusts of 40 to 60 mph.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOU wrote it up.
High based showers track across northeast Colorado on the afternoon and evening of June 25th producing wind gusts of 40 to 60 mph.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Denver/Boulder, CO wrote its last area forecast discussion before the first event at Jun 25, 1:51 PM MST, 9 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Denver/Boulder CO 251 PM MDT Tue Jun 25 2024 .KEY MESSAGES... - Heat continues Wednesday and Thursday, though not as hot as earlier this week with lower 90s across the plains and urban corridor. - Increasing chances for thunderstorms Wednesday (30-60% high country; 20-40% Plains) and Thursday (50-80% high country; 30-60% plains). A few could be strong to severe. && .SHORT TERM /Through Wednesday/... Issued at 250 PM MDT Tue Jun 25 2024 A ridge of high pressure continues across Colorado. From this afternoon through Wednesday evening the ridge doesn't move much, in fact slightly higher heights might even build in from the south. The center of the ridge is squarely over the U.S. Desert Southwest and northern Mexico. Flow at 500 mb and above is not surprisingly fairly weak with northwest flow 15-30 kts going west-southwest by Wednesday afternoon. However, closer to the surface things do change a little by Wednesday morning--a very weak trough at 700 mb moves across the northern Rockies on Wednesday with 20-30 kts of southerly flow ahead of it. Believe it or not, this air is a little bit cooler and quite a bit more moist than the air masses over the last few days. Here is what to expect at the surface: Weak convective showers should be over by midnight across our area, and any rainfall amounts will be very light. Skies will gradually clear with much less convective cloud debris aloft vs last night. That, combined with weaker winds near the surface will result in better nighttime cooling than the previous few nights. This should be true especially across the western suburbs where it was breezy all night last night with temps steady in the 70s. All areas, including the urban heat islands, should cool of nicely into the low to mid 60s tonight, same as the rest of the plains. The mountain valleys will also nicely cool into the upper 40s. On Wednesday moisture advection should begin in earnest ahead of the 700 mb trough, and combined with robust east winds just off the surface, should increase PW to near 1.5" across the eastern plains, and between 1-1.2" along the I-25 corridor, and 0.7" along the Divide and West Slope. HREF mean SBCAPE values are 700-1000 J/kg for most of the plains, including Larimer and Weld Counties. Across metro Denver the models don't look bullish on brining in much low-level moisture. Lapse rates are pretty weak in the high country, so even though storms will get going by midday, they will be weak with just light rainfall. Given the better low-level moisture across the northern half of the I-25 corridor, PoPs are highest for Larimer and Weld Counties once convection moves off the mountains. When outflow boundaries/existing convection get far enough east into the richer moisture and instability, mostly along and east of a Fort Morgan to Limon line, better chances of thunderstorms (> 50%) are forecast into the evening hours. 0-6 km shear of about 40 kts should support strong storms, with a one or two possibly severe across the eastern Plains, where SPC has a marginal risk of severe storms. Even though there will be uptick in cloud cover and storm coverage, afternoon max temperatures will still be hot, with highs 90-95 across the plains, and 75-85 in the mountain valleys. && .LONG TERM /Wednesday night through Tuesday/... Issued at 250 PM MDT Tue Jun 25 2024 Wednesday night an upper level ridge of high pressure will be over the Rocky Mountain Region and Central Plains States with a weak to moderate westerly flow aloft over Colorado. Scattered showers and storms (25%-50%) will continue into the evening, most numerous across the plains east and northeast of Denver. With MLCAPES over 1000J/KG some of the storms from the Front Range Urban Corridor eastward across the plains could be strong to severe. In addition, with high PW's ranging between 0.60" to 1.00" in the high country and 1.15 to 1.60" across Northeastern Colorado, heavy rainfall will also be a possibility. On Thursday, the upper ridge flattens in response to an upper level trough moving across the Northern Rockies. This will put Colorado under the influence of a moderate westerly flow aloft. With plenty of available moisture and instability, along with some lift from a 60KT upper level jet, we should see another round of afternoon and evening showers and storms move across the forecast area. Some of storms could produce heavy rain with the potential for a couple of strong to severe storms further east across the plains. On Friday, a somewhat cooler and drier airmass advects into the region as an upper level shortwave moves into the Northern Plains States and the upper level flow turns more northwesterly. As a result, shower and thunderstorm activity is expected to decrease somewhat. A cold front is expected to move across Northeastern Colorado Friday night resulting if cooler more stable day on Saturday with a chance (30%-50%) of afternoon and evening showers and storms mainly across the Front Range Mountains, foothills and Palmer Divide. Some of these storms could produce brief heavy rainfall. On Sunday, upper level high pressure builds over the Southern Plains States with an upper level trough of low pressure over the Western U.S. This pattern may allow some subtropical moisture to flow into Colorado from the south and southwest, which may bring an uptick in shower and thunderstorm activity to the high country. Despite the increase in moisture, models are showing light QPF in the mountains. Still think there is a remote chance that a storm in the high country could produce locally heavy rainfall, mainly south of I-70. Further east across the plains, thunderstorm activity may be limited due to lower dewpoints and more stability. However, can't rule out a stronger storm due to local moisture convergence. Hot and mostly dry weather is expected early next week as a dry westerly flow aloft sets up over Colorado. && .AVIATION /18Z TAFS through 18Z Wednesday/... Issued at 1105 AM MDT Tue Jun 25 2024 VFR through Wednesday and with hot temperatures both this afternoon and Wednesday afternoon. There shouldn't be any showers at the terminals this afternoon, but one or two wind shifts with gusty winds are expected. For now, the most likely wind shift looks to be west, northwest, or north given where some weak convection should be ongoing this afternoon. We will continue to handle the potential wind shifts with a TEMPO group for VRB gusts to 30 kts. Tonight will be a normal drainage wind night (SSW at APA and DEN 8-12 kts; WSW at BJC 5-9 kts). On Wednesday, winds should shift to the ESE and maybe gust over 20 kts from midday until storms gets going and move of the mountains. Thunderstorm coverage will be much more than that past couple of days. Those storms may directly impact the terminals, but it's about a 40 percent chance of a storm going overhead. It's almost a guarantee that several gust fronts will move across the terminals with a wind shift and gusty winds to 35 kts. && .HYDROLOGY... Issued at 250 PM MDT Tue Jun 25 2024 The potential for heavy rainfall will increase across North Central and Northeastern Colorado Wednesday and Thursday as subtropical moisture moves over Colorado from the south and southwest. Storm motions will be slightly faster Thursday, helping to taper the threat of flash flooding. Isolated to scattered afternoon thunderstorms will continue beyond Thursday, but moisture will generally be more limited, thereby reducing the potential for heavier rainfall. .BOU WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM MDT this evening for COZ040. && SHORT TERM...Schlatter LONG TERM...JK AVIATION...Schlatter
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1044 AM MDT Tue Jun 25 2024 COZ030>051-261645- Jackson County Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- Grand and Summit Counties Below 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Central and Southeast Park County- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 1044 AM MDT Tue Jun 25 2024 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight It will be another very warm to hot day across northeast Colorado with highs in the mid to upper 90s. Isolated gusty showers and thunderstorms will develop this afternoon bringing wind gusts to 40 mph. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Moisture is expected to increase Wednesday and Thursday bringing better chances for showers and thunderstorms, some of which could produce heavy rain and small hail. An isolated severe storm will be possible over the northeast plains both days as well. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight.
Special Weather Statement
National Weather Service Denver CO
235 PM MDT Tue Jun 25 2024
COZ033-035-252100-
Larimer and Boulder Counties Between 6000 and 9000 Feet CO-
South and East Jackson/Larimer/North and Northeast Grand/Northwest
Boulder Counties Above 9000 Feet CO-
235 PM MDT Tue Jun 25 2024
...STRONG THUNDERSTORMS WILL IMPACT NORTH CENTRAL LARIMER COUNTY
THROUGH 300 PM MDT...
At 233 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 8 miles southwest of Tie Siding to 6 miles
southwest of Pingree Park, or along a line extending from 21 miles
south of Laramie to 32 miles west of Fort Collins. Movement was east
at 25 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Kinikinik, Pennock Pass, Rustic, Cherokee Park, Red Feather Lakes,
and Pingree Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Prepare for sudden gusty winds. Secure loose objects and move to a
safe shelter inside a building or vehicle.
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4051 10542 4053 10581 4100 10573 4100 10534
TIME...MOT...LOC 2033Z 272DEG 20KT 4101 10563 4053 10569
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
RPKThe national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Buckeye RAWS gusted to 64 mph and mesonet station UP1718, 4.8 miles north of Nunn reported a 58 mph wind gust.
The Fort Morgan AWOS reported a 59 mph wind gust with a passing shower.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2024Every state in 2024This day in weather historyWarnings in Colorado, June 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1177271, 1177273.